Generalized Degrees of Freedom of the Interference Channel with a Signal Cognitive Relay

Abstract

We study the interference channel with a signal cognitive relay. A signal cognitive relay knows the transmit signals (but not the messages) of the sources non-causally, and tries to help them communicating with their respective destinations. We derive upper bounds and provide achievable schemes for this channel. These upper and lower bounds are shown to be tight from generalized degrees of freedom point of view. As a result, a characterization of the generalized degrees of freedom of the interference channel with a signal cognitive relay is given.Comment: Results submitted to ISIT 2010, 19 pages, 3 figure